Radiation effects on Premium Q and Supreme Q cultured quartz crystals

Premium Q and supreme Q are the grades of high quality commercially available cultured quartz from Sawyer Applied Research Products, OH and Toyo Communication Equipment Company, Kawasaki, Japan. These grades of materials are generally used as resonators in high precision frequency control applications. These crystals are essentially identical in terms of their quality factor Q, except for the type of charge compensators at Al³⁺ sites. While premium Q quartz has Li⁺ as charge compensators at Al³⁺sites, in the supreme Q material the aluminium is compensated with Na⁺. Our thermoluminescence (TL) investigations suggest that both the types of crystals, in addition to Al and its charge compensators also have Ge and Ti as impurities present in these materials. The TL peak of Ti-related center seems larger in intensity than that of Ge associated centers. However, the relative strengths of these peaks are not directly related with their concentrations. Complimentary investigations on radiation effects using cathodoluminescence and ESR spectroscopy have also been done. Results are discussed in terms of fundamental defect structures in quartz.